Abstract

The ribonucleic acid viruses represent an anomaly in the biological world, being its only known entities which lack deoxyri-bonucleic acid. Nevertheless, these viruses readily transmit genetic characters, they can be mutated by agents which affect DNA (1) , and their RNA is sufficient to determine their heritable characteristics (2). In the light of present knowledge of genetic mechanisms, especially as elucidated by the work of Jacob and Monod (3), it is generally believed that viral RNA can function as a type of messenger RNA and experimental support for this notion exists (4). This leaves open the question of how RNA can duplicate, since cellular messenger RNA does not appear to be directly replicated, but is a complementary copy of DNA. The work described here was undertaken in an attempt to clarify the mechanism of viral RNA duplication.